First print Prusament PETG  

RE: First print Prusament PETG

Posted by: @ooj

Hello, 🙂 

I need to print myself another MMU2 Selector Finda and as the original is PETG I figure I would print a new one in PETG, so having purchased Prusament PETG Orange 😊  I've looked at guides for printing with PET/PETG and blue tape is mentioned, I've seen Windolene mentioned as an adhesive, hairspray. I have a couple of questions regarding print surface as I have a Textured PEI surface,  should I use the Textured PEI print surface, if so, does it need Windolene to be sprayed on to it first?

Thanks in advance for your help. 🙂 

Printing PETG with the textured pei sheet works very well with about 230-240degree C nozzletemp and 90degree C bedtemp. No tape and no glue is needed. Very important is a top first layer calibration and absolutly clean bed. Before you remove the printed part, you should let cool down the bed. Maybe use a brim (5-10mm).

RE: First print Prusament PETG

I'm having some similar issues with PETG.  Textured PEI sheet.  I think I've got a clean sheet, but it's hard to say.  

My primary issue:

The skirt isn't sticking well.  When the 2nd layer starts, it lifts the initial skirt off the bed, then proceeds to drag it around the model like a miniature wrecking ball.  I also have some issues with the corners lifting.
Any thoughts on how to fix.  My first layer looks good, but isn't adhering well.  I'm using IPA followed by vinegar/dish soap glass cleaner (I don't have any Windex).  Should I try the glue stick?

RE: First print Prusament PETG

No glue stick... Should never be needed with PETG.

Switch your skirt with a brim. Skirts are also high temperature solutions.

With nothing to go on - I will boldly say your problems are cleanliness and/or first layer Z.

Start with a good scrub with dawn and copious water. Dry with a clean paper towel. Never touch the print area.

Next, read this:

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

Print a good calibration square or circle and post it here. No IPA for this - just the scrub. You can get lots of advice based on how that looks.

RE: First print Prusament PETG

Hello, 😀 

Thank you for your help karl-herbert and robert-rmm200. 🙂 

12 calibration squares of 80x80x0.2, I like the way they show surface deviations of your print surface.  Printing all those calibration squares was a tedious but interesting time and having done that I think I have found a sweet spot.

I used the Prusament PETG material preset in Prusa Slic3r to print all the calibration squares.

I now have a replacement MMU2 Selector Finda. 😀 

RE: First print Prusament PETG

Doing some experimenting, I was definitely too high by about 0.05mm, which was giving me adhesion issues between layers.  Going lower has definitely fixed that.  

The upper left is -1.400 (good?), the middle strip is -1.500 (too low), and the lower-right is -1.450 (still looks low).  I'm running another with -1.375 (looks too high initially), and -1.425 (looks ok).  It looks like my setting should be somewhere around -1.400, I'm going to look at the -1.425 sample and decide if I want to be at -1.400 or -1.410 or -1.415.  

RE: First print Prusament PETG

Posted by: @robert-rmm200

[...] No glue stick... Should never be needed with PETG.

In general, agreed. Just a cautionary note that some high-temp PETGs (e.g. 3DXTech) prints at 270C and will definitely require some sort of separator beyond the usual Windex or finger grease. I lost my 1st PEI stick sheet to the stuff. Glue stick or MagiGoo may be needed for exotics.

RE: First print Prusament PETG

For prints where I was having some tear up or adhesion issues, I set the bed temp a little higher (90 for PETG) for the first layer and used the manual feed rate override to slow things down.  It may be overkill but I usually wind it down to about 70%.  Once I started doing these things, I've not had any issues.  As a result of investigating another issue, I see know that PrusaSlicer has a Printer First Layer speed override that I'll start using from here on out.